The attachment used most commonly on tractor front-end loaders is a bucket made of steel, having a bottom (or “floor”), a back, two sides, a short top near the back, and one or two components, which we call yokes, welded to the back, for connecting the attachment to the front-end loader hydraulics. The bucket is small enough and strong enough so that it is highly suitable for loading material such as dirt, sand, and gravel by driving the tractor forward to push the bucket into a pile of such material. The bucket is also capable of digging down into the ground a short distance and scooping up dirt. The bucket can be lifted and tilted by the hydraulic system, and in particular can be tilted downward so as to unload the bucket by spilling the material out of it.
A disadvantage of the bucket is that its volume and floor area are too small for many applications that do not require scooping but do require carrying or lifting a large volume or large area of objects or materials. Typical dimensions for a wide range of tractors are a width of five or six feet and a depth and height of about two feet or less, giving a volume of 24 cubic feet or less and an area of 12 square feet or less. The side walls give the bucket strength and rigidity but inhibit its use for carrying objects longer than the bucket width.
Another attachment available for tractor front-end loaders is a fork lift, which might be attached to the front of the bucket or directly to the hydraulics. This device permits lifting material placed on pallets, and also carrying long objects that rest on the forks. A disadvantage is that the attachment is not suitable for lifting or carrying many objects that are not on a pallet and are not long enough or stiff enough to lay across the forks, such as sticks and short log segments, tools, fencing, nursery stock, roofing materials, masonry, firewood, fertilizer and seed bags, straw bales, and many more.
A third type of attachment for tractor front-end loaders is a hay fork, designed for lifting and carrying large round or square hay bales. It clearly has the disadvantages described in the preceding paragraph for the fork lift.
Yet another attachment (U.S. Pat. No. 4,992,020) has a solid bottom and back, without sides, that make it suitable for carrying both long objects that extend beyond the sides, and also small objects or material that are placed on a portion of the bottom surface. The bottom of the attachment includes two plates fastened together at a small angle to form a wedge or thin triangular shape when viewed from the side. These plates are separated and held in position by several triangular supporting plates as well as several other reinforcing plates. The back of the attachment consists of an I-beam and two yokes. The physical embodiment of this device comprises steel plates welded together. The manufacturing process would be quite sophisticated, as the individual components would require extensive cutting and welding. The volume of the device, for stacking material such as brush, would be relatively small unless the I-beam back were high (e.g., 3 or 4 feet) and wide (e.g., 8 feet or more), in which case the weight and material cost would also be very high. No tests of the strength or capacity of the attachment were provided, and it is not clear that this design is particularly strong relative to its complexity, weight, and cost. In general, the very high cost of materials and the extremely high cost of cutting and welding the steel components, in order to fabricate the implement, make this design highly inefficient and impractical for the lifting and carrying functions that are the purpose of the front-end carrier.
The front-end carrier of the present invention permits multiple embodiments or aspects that provide several advantages over the devices just discussed, and may include any or all of the following advantages: First, the aspects have a relatively large capacity with respect to both volume and area. This capacity is roughly similar to that of the bed of a full-size pickup truck. Second, the aspects can carry many small objects lying on the deck. Third, the aspects can conveniently carry objects that are longer than the width of the aspect. Fourth, the aspects can be made relatively cheaply, largely from common, off-the-shelf materials with simple fabrication techniques. Fifth, the aspects can be used as a scaffold, with a large area for standing, moving around, storing tools and material, etc. Sixth, the aspects can be marketed in a few different states of assembly, making shipping more economical. These and other advantages of one or more aspects of the carrier will be evident from the embodiments discussed below and will be discussed in more detail in a later section.